The MagickWand interface is a new high-level C API interface to ImageMagick core methods. We discourage the use of the core methods and encourage the use of this API instead. Post MagickWand questions, bug reports, and suggestions to this forum.

ImageMagick supports OpenCL. If enabled, it will try to run certain operations on the GPU such as resizing, convolving, blurring, etc. However, it does not accelerate reading or writing images. If you want ImageMagick to yield the CPU, you can add a throttle policy to the policy.xml configuration:

<policy domain="resource" name="throttle" value="2"/>

Alternatively you are force the pixel cache to disk rather than memory with the -limit memory 1MB, -limit map 1MB command line options. This increases I/O and permits the CPU to attend to other processes on your device.